The SINMAP Approach to Terrain Stability Mapping
A promising approach to modeling the spatial distribution of shallow debris slides combines a mechanistic infinite slope stability model with a steady-state hydrology model. The spatial distribution of a “stability index” is governed primarily by specific catchment area (the upslope area per unit contour length) and slope. The model can be interactively calibrated to the unique characteristics of the topography, rainfall, and soils of a particular study area using simple parameters, graphs and maps. Once a landslide and terrain inventory is completed using aerial photographs, this approach is shown to have the capability of producing a stability classification map of a huge area in a very short time. An analysis of the Kilpala watershed of northern Vancouver Island, British Columbia is presented as an example.